Disk reproducing apparatus and method for reproducing an audio signal and a subcode at N times normal speed from a disk

ABSTRACT

A disk reproducing apparatus is provided which can cope with the intermittent access due to track jump in the conventional CD reproducing system and which can reproduce data at N times the normal speed and produce the reproduced data at the normal speed. The disk reproducing apparatus includes a memory for storing the data and time information reproduced from the disk to match with each other, another external memory, a detection circuit detecting the time difference between the finally produced output data and the data which is being accessed, and a control circuit detecting the overflow/underflow of the external memory and controlling it to be written. The construction can absorb the time difference between the system operation speed and data output speed even during an intermittent access so that continuous data can be produced.

BACKGROUND OF THE INVENTION

The present invention relates to a disk reproducing apparatus, andparticularly to a disk reproducing technique suitable for use inreproducing data at an N time normal speed from a disk on which maininformation has been recorded together with a subcode of timeinformation or the like, such as a digital audio disk.

There is a known an example of data reproduction in which anintermittent access results when the information reading means isinadvertently moved by an external force or the like during N-timenormal speed reproduction of a disk where N is a positive integer. Thatis, as described in JP-A-62-150560, (Shibuya) digital audio datareproduced from a compact disk (CD) is written in a memory, but when theinformation reading means inadvertently skips over tracks, it is movedback to its previous position from which the skipping occured. At thistime, the writing of the data reproduced from the disk into the memoryis stopped and the memory is read at a constant period of the samplingfrequency. Thus, the digital-to-analog converted data can becontinuously reproduced.

In this known method, during the period in which the information readingmeans is inadvertently moved, or skips over tracks and is then movedback to the original correct position, no noise occurs, and thereproduction is not interrupted, or abnormally carried out. However,data control is not performed for making data precisely continuous. Thisis because although the subcode of time information is produced in timewith the disk reading operation, the audio data is first written in amemory in order that the rotation irregularity of the disk can beabsorbed, and is read thereafter under the control of a crystaloscillation frequency. Thus, the subcode and the audio data cannot bemade precisely coincident in one-to-one correspondence.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a diskreproducing apparatus capable of precisely coordinating the subcode(e.g., sector number, time information, etc.) with the main informationdata in one-to-one correspondence and of making the data preciselycontinuous by use of the resulting main information data and subcode.

It is another object of the present invention to provide a diskreproducing apparatus in which the switching for the equalizer and clockreproduction is not necessary for the N-time normal speed output and thenormal speed output because the subcode and the main information dataare coincident in one-to-one correspondence, and because the data can bemade continuous by use of the resulting main information data andsubcode even when the data is read intermittently from the disk.

According to one feature of the present invention, there is provided adisk reproducing apparatus which includes processing means fordemodulating modulated information data and a subcode read by theinformation reading means, making a certain process to detect or correctan error in the information data, and for producing the information dataand the subcode; first memory means for storing the information data orthe information and subcode from the processing means and for producingthe information data, and first control means for controlling a writeaddress and read address supplied to the first memory means, theprocessing means including second memory means for storing theinformation data and the subcode in order to absorb a rotationirregularity of the disk, and second control means for controlling awrite address and read address supplied to the second memory means, thewrite address and read address supplied to the second memory means beinggenerated from the second control means in order to deinterleave andread the information data which has been interleaved upon recording, sothat a particular one of the information data and particular one of thesubcode can be read in one-to-one correspondence.

According to another feature of the present invention, the first controlmeans for controlling the write address and read address supplied to thefirst memory means includes first detecting means for detecting firstsector information which indicates an address at which the informationdata is written in the first memory means from the subcode which isproduced from the processing means through the second memory means;second detecting means for detecting second sector information whichindicates an address at which the information data is read from thefirst memory means; third detecting means for detecting overflow andunderflow of the data stored in the first memory means by comparing thedetected first sector information and second sector information; thirdcontrol means for inhibiting the first memory means from being writtenwhen the third detecting means detects an overflow and produces aresulting output; fourth control means for moving the reading means to aposition of next data continuous to the previous data according to thefirst sector information when the first memory means is inhibited frombeing written; and fifth control means for releasing the first memorymeans from the write-inhibited state, thereby enabling the first memorymeans to be written when the third detecting means detects an underflowand produces a resulting output, wherein a first clock frequency fordetermining the speed at which a data is written in the first memorymeans corresponds to N times the normal speed, and a second clockfrequency for determining the speed at which a data is read from thefirst memory means corresponds to the normal speed.

According to the above features of the present invention, since theprocessing means having the second control means is provided, thesubcode can be written in and read from the second memory means, and thesubcode and information data on the disk can be maintained to be matchedwith each other since the disk rotation irregularity can be absorbedfrom both the subcode and information data.

In addition, since the first control means and the first memory meansare provided, the data reproduced from the disk which is rotating at Ntime normal speed can be buffered and the reproduced data can becontinuously read from the memory means at the normal speed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a disk reproducing apparatus with anexternal PAM according to the present invention.

FIGS. 2A--2C are diagrams showing the subcode format of CD.

FIG. 3 is a block diagram of the disk reproducing apparatus of FIG. 1,with the CD signal processing circuit shown in detail.

FIG. 4 is a block diagram of the address control circuit-2 10 in FIG. 3.

FIG. 5 is a block diagram of the address control circuit 1 in FIGS. 1and 3.

FIG. 6 is a CD-ROM disk reproducing apparatus according to the presentinvention.

FIGS. 7A and 7B are respectively timing charts for the twice normalspeed CD-ROM writing and reading and for the twice normal speed writingand normal speed reading.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

An embodiment of a compact disk (CD) reproducing apparatus of thepresent invention will be described with reference to FIG. 1 showing theCD reproducing apparatus and FIG. 2 showing the subcode format of theCD.

Referring to FIG. 1, there are shown a disk 1, a motor 2 for rotatingthe disk, a pickup servo circuit 3, a motor servo circuit 3', a pickup 4for reading data from the disk, a preamplifier 5, a conductor 8 carryinga subcode 8 including time information, access data line 13 carryingaudio data which has been subjected to a certain process and the subcodeadded to the audio data, a CD signal processing circuit 14 forprocessing the data reproduced from the disk, for adding a subcode tothe data and for producing the subcode-added data, a RAM-1 15 forstoring the access data received on line 13, address information line 16for accessing the RAM-1 15, output data line 17, and a time informationdetector 18 for detecting time information from the access data on line13 and from read information on line 24 sent from a microcomputer 21. Inaddition, there are shown an address control circuit-1 19 including thetime information detector 18, overflow/underflow information line 20 forindicating an overflow/underflow condition of the RAM-1 15 from the timeinformation detector 18, the system control microcomputer 21,intermittent access information lines 22, 23 providing signals based onthe overflow/underflow information on line 20, the information line 24carrying information read from the disk, a read clock line 42 by whichdata is read from the RAM-1, a read clock generator-1 44 for generatingthe read clock for normal speed reading, a read clock generator-2 45 forgenerating the read clock for N-time normal speed reading, and aswitching signal line 46 for the read clocks.

The digital signal reproduced from the CD includes audio data and asubcode. This subcode, as shown in FIG. 2A, is arranged in the areaimmediately following each frame synchronizing signal and is composed of8 different channels P through W as shown in FIG. 2B. Each group of 98subcodes (i.e. subcodes for 98 frames) included as subcodes S0, S1 atthe beginning of each frame, establishes significant data. As shown inFIG. 2C, the Q-channel of the subcode has the time information and acontrol signal recorded, therein and an error detection code is added sothat the subcode can be reproduced with high reliability.

The operation of the CD reproducing apparatus with the above mentionedconstruction will be described below.

Referring to FIG. 1, the disk 1 is rotated at a N-time normal speed bythe motor 2. The pickup 4 is controlled to read data by the pickup servo3. The read data from the pickup is supplied through the preamplifier 5to the CD signal processing circuit 14. The reproduced data is processedby the CD signal processing circuit 14, and as a result, the CD signalprocessing circuit 14 produces at N times the normal output rate theaccess data 13 on line representing the audio data having the subcode 8which includes time information.

The access data on line 13 of N-time normal output rate thus produced issupplied to the RAM-1 15 where it is written, and the stored data isread at the normal speed (one time normal speed), under the control ofthe address control circuit-1 19.

Here, the operation of the address control circuit-1 19 and theperipheral circuits will be described in detail. The address controlcircuit-1 19 generates a write address on line and read address 16 tothe RAM-1 15, and the system control microcomputer 21 decides from thesubcode 8 whether the information from the audio disk is data or audiodata. As a result, the system control microcomputer 21 produces aswitching control signal on line 46 for selecting the read clockgenerator-1 44 for normal speed. Thus, the access data 13 produced atthe N-time normal speed output rate from the CD signal processingcircuit 14 and stored in the RAM-1 15 is read from the RAM-1 15 at thenormal speed. In other words, since the CD signal processing circuit 14operates at N-time normal speed, the access data is written in the RAM-115 at N times the normal speed, while the stored data is read from theRAM-1 15 at the normal speed (one time normal speed). In this situation,since data overflows from the RAM before all data is read, the addresscontrol circuit-1 19, including the time information detector 18 and thesystem control microcomputer 21 control the writing and readingoperations. The time information detector 18 of the address controlcircuit-1 19 detects the time information at the time of writing on thebasis of the access data on line 13, and at the same time it detects thetime difference between the writing and reading operations on the basisof the disk read information 24, in order to check whether the RAM-1 15overflows with data or not on the basis of the detection result of thetime difference information. If an overflow is detected, it produces theinformation 41 for inhibiting data from being written in the RAM-1 15,thereby stopping the writing operation, and supplies the overflowinformation 20 to the system control microcomputer 21. The systemcontrol microcomputer 21 produces intermittent access information 22, 23on the basis of this overflow information 20 and the time information atthe time of writing inhibition. As a result, the pickup servo 3 controlsthe pickup 4 to move to the position on the disk where the next data canbe made continuous to the previous one. If an underflow is detected, thetime information detector 18 produces the information 41 for releasingthe RAM-1 15 from the writing-inhibited state, and supplies theunderflow information 20 for reaccess to the disk to the system controlmicrocomputer 21. Thus, the pickup 4 reads the next data forcontinuation from the disk, and after each process the read data isagain started to be written in the RAM-1 15.

According to this embodiment, the data produced at N times the normaloutput rate from the CD signal processing circuit 14 is first stored inthe external RAM, and is then read therefrom at the normal speed, andthe writing and reading operations of the RAM are controlled so that thetime difference between the N-time normal speed of the system and thenormal speed output of data is absorbed with the output data beingcontinuously produced.

The CD signal processing circuit 14 of the compact disk (CD) reproducingapparatus of the invention will be described in detail with reference toFIGS. 3, 4 and 5. FIG. 3 shows the CD reproducing apparatus of FIG. 1with the CD signal processing circuit 14 being shown in detail. In FIG.3, like elements corresponding to those in Fig. 1 are identified by thesame reference numerals. FIG. 4 diagrammatically shows the addresscontrol circuit-2 10 shown in FIG. 3, and FIG. 5 diagrammatically showsthe address control circuit-1 shown in FIGS. 1 and 3.

Referring to FIG. 3, the CD signal processor 14 includes a demodulatingcircuit 6 for demodulating the reproduced data, audio data line 7, adata bus 9, the address control circuit-2 10 for controlling thewrite/read address to, a RAM-2 11 for storing the reproduced data, andan audio data processing circuit 12 for processing the audio data.Referring to FIG. 4, there are shown a write address generator 25 forgenerating the write address 26 to the RAM-2, the RAM-2, a read addressgenerator 27 for generating the read address 28 to the RAM-2, an addressmonitoring circuit 29 for monitoring the write address 26 and readaddress 28 to the RAM-2 and for controlling the difference to be within±four frames, and an address switching circuit 30 for switching thewrite address 26 and the read address 28.

Referring to FIG. 5, there are shown a time information detectingcircuit-1 31 for detecting time information on the basis of the accessdata 13 produced from the CD signal processing circuit 14, timeinformation-1 32 from the time information detecting circuit-1 31, awrite address generator 33 for generating the write address to the RAM-1on the basis of the time information-1 32, a time information detectingcircuit-2 34 for detecting time information indicating when the RAM-1 15produces an output in response to the address information 16, timeinformation-2 35 from the time information detecting circuit-2 34, aread address generator 36 for generating the read address to the RAM-115 on the basis of the time information-2 35, a difference detectingcircuit 37 for detecting the difference between the time information-132 and the time information-2 35, the difference information 38 from thedifference detecting circuit 37, an overflow/ underflow detectingcircuit 39 for detecting the overflow and underflow of the RAM-1 15 onthe basis of the difference information 38, a write control circuit 40for inhibiting the RAM-1 15 from writing upon over-flow and releasing itfrom the inhibited state upon underflow on the basis of theoverflow/underflow information 20 of the RAM-1 15, and write information41 from the write control circuit 40.

The operation of the circuits will be described below.

Referring to FIG. 3, the disk 1 is rotated by the motor 2, and thepickup 4 is controlled to read data and to supply it through thepreamplifier 5 to the CD signal processing circuit 14 by the pickupservo 3. The reproduced data supplied to the input of the CD signalprocessing circuit 14 is demodulated by the demodulating circuit 6 intoaudio data 7 and a subcode 8. The subcode 8 is directly passed throughthe CD signal processing circuit 14. The audio data 7 is written in theRAM-2 11 under the control of the address control circuit-2 10 so thatthe jitter due to the disk rotation irregularity is absorbed and that anerror correction and interleaving process can be performed by the audiodata processing circuit 12. At this time, the subcode 8 is written inthe RAM-2 11 together with the audio data 7. The audio data 7 andsubcode 8 written in the RAM-2 11 are read from the RAM by the addresscontrol circuit-2 10. The audio data 7 is subjected to an interpolationprocess in the audio data processing circuit 12, and then produced fromthe CD signal processing circuit 14 as the access data 13 with thesubcode added.

The operation of the address control circuit-2 10 will be furtherdescribed with reference to FIG. 4. As shown in FIG. 4, the writeaddress 26 to the RAM-2 11 is generated from the write address generator25 at a reproducing system clock synchronized with the reproducedsignal. The read address 28 to the RAM is generated from the readaddress generator 27 at a crystal oscillation clock frequency. Thesubcode in the prior art is not written in the RAM, but is producedtimely with the disk reading operation in order to occur at the positionwhere the disk is read. In contrast, in accordance with the invention,the subcode 8 as well as the audio data 7 is written in and read fromthe RAM-2 11 through the data bus 9. At this time, the write address 26and the read address 28 are switched by the address switching circuit30. The address monitoring circuit 29 maintains the distance between thewrite address and the read address to be within ±four frames to absorbthe disk rotation irregularity.

The time information detector 18 of the address control circuit-1 19detects time information from the access data 13, as shown in FIG. 3,and data is fully written in the RAM-1 15 and stopped from being writtentherein. The time information detector 18 detects time differenceinformation on the basis of the access data 13 and disk readinginformation 24. On the basis of the detected time differenceinformation, it monitors whether the RAM-1 15 overflows or not, detectsthe address for the next continuous data, and supplies to the systemcontrol microcomputer 21 the overflow/underflow information 20 forreaccess to the disk.

The operation of the address control circuit-1 19 including the timeinformation detector 18 will be further described with reference to FIG.5. In the time information detector 18, as shown in FIG. 5, the timeinformation detecting circuit-1 31 detects the time information of theaccess data 13 from the CD signal processing circuit 14, and the timeinformation detector-2 34 detects the time information at the time ofproducing an audio output from the read address to the RAM-1 15, whichis generated on the basis of the disk reading information 24. The writeaddress generator 33 generates a write address to the RAM-1 15 on thebasis of the time information-1 32 from the time information detector-131. The read address is generated from the read address generator 36 ata rate of a read clock 42 on the basis of the disk reading information24 from the system control microcomputer 21. The address switchingcircuit 30' switches the write address signal and the read addresssignal and produces the address information 16. The difference detector37 detects the difference between the time information-1 32 forgeneration of the write address and the time information-2 35 which isproduced on the basis of the read address, and produces differenceinformation 38. The overflow/underflow detector 39 detectsoverflow/underflow information of the RAM-1 15 on the basis of thedifference information 38. The write control circuit 40 produces thewrite inhibit information 41 upon overflow on the basis of theoverflow/underflow information 20 of the RAM-1 15.

The overflow/underflow information 20 and the subcode 8 at the time ofwrite inhibition are used by the system control microcomputer 21 toproduce the intermittent access information 22, 23. Thus, the pickupservo 3 controls the pickup 4 to move to the position where the nextdata is read which is continuous to the previous data.

When the overflow/underflow detector 39 detects an underflow, the writecontrol circuit 40 produces the write inhibit releasing information 41,and the next data which is continuous to the previous data is read bythe pickup 4, subjected to each process and started to be rewritten inthe RAM-1 15.

According to this embodiment, since the audio data produced from the CDsignal processing circuit has time information added, thereto thejunction between data can be precisely detected, and since the timedifference can be absorbed by the external RAM other than the CD signalprocessing circuit, the output data can be continuously reproduced.

Another embodiment of the invention, or a CD-ROM reproducing apparatuswill be described with reference to FIGS. 6 and 7. FIG. 6 is a blockdiagram of a CD-ROM disk reproducing apparatus. In FIG. 6, like elementscorresponding to those in FIGS. 1 and 3 are identified by the samereference numerals. FIGS. 7A and 7B are timing charts useful forexplaining the operation of the address control circuit-1 19 shown inFIG. 6 which timing charts are respectively provided for the twicenormal speed writing and reading and for the twice normal speed writingand normal speed reading.

Referring to FIG. 6, reference numeral 43 represents a CD-ROM signalprocessing circuit having the address control circuit-1 19 with the timeinformation detector 18.

The construction shown in FIG. 6 is able to reproduce data at twicenormal speed from the CD-ROM disk which is worth using as a data base.When a CD disk for music signals is reproduced by this construction, thesignal processor operates at twice normal speed, and the output data isproduced at the normal speed. The CD-ROM is a system for managing datain sector units of 98 frames each. Thus, in order to reproduce a CD onthe CD-ROM reproducing apparatus, it is necessary that a signal similarto the sector number be added to the reproduced data from the CD.

The operation will be described with reference to FIG. 6 and FIGS. 7Aand 7B.

When a data disk is being read, whether the data is audio data or not isdetermined from the subcode 8, and the system control microcomputer 21generates a switching signal 46 and thereby selects the generator-2 45for a twice-normal speed read clock, so that the output data 17 isproduced at twice normal speed, as shown in FIG. 7A.

When an audio disk is being read, whether the data is audio data or notis determined from the subcode 8, and the system control microcomputer21 produces the switching signal 46 and thereby selects the generator-144 for a normal speed read clock, so that the output data 17 is producedat the normal speed, as shown in FIG. 7B. The signal processing systemfor CD-ROM operates at twice normal speed, and data is written in theRAM-1 15 at twice the normal speed. Upon reading, data is read from theRAM-1 15 at the normal speed (one time normal speed), and thus the RAMoverflows before all data is read. According to the idea of theinvention, since the audio data 7 is accompanied by with the subcode 8of 98 frame units which includes time information and is produced fromthe CD signal processing circuit 14, data can be in sector units. Thus,the correct junctions can be detected for the detection of the timedifference, and the RAM-1 15 absorbs the time difference between thetwice normal speed of the system and the normal output speed of theoutput data 17. In FIGS. 7A and 7B, data stored last in the firststorage means before the time point (A) is represented by n+k. Inaddition, j represents an integer larger than zero. The number of thesector in the other period between time points (A) and (B) is increasedone by one at every period T.

According to this embodiment, since the access data 13 has the subcodeof 98 frame units, the access data 13 is written in the RAM-1 15, andthe address control circuit-1 19 of the CD-ROM signal processing circuit43 detects the time difference between the output data and the accessdata. Also, the overflow/underflow of the RAM-1 15 is measured and theintermittent access information 22, 23 is fed to the servos. The time isagain detected for the detection of correct junctions. Thus, thisembodiment can be used as a CD-ROM system in which data is written inthe external RAM at N times the normal speed and read at the normalspeed, and the circuits can be shared by both systems.

In addition, this invention can be applied to a minidisk (MD) system inwhich data is compressed to 1/5 the original size.

According to this invention, even if an intermittent access is made dueto a track jump or the like, the junction of the data can be preciselydetected since time information is added to the data which is producedfrom the signal processor, and thus the output data can be continuouslyproduced.

Moreover, when data is first written in the external RAM, and then readtherefrom, the time difference between the written data and the readdata is detected. When an overflow of the RAM is detected, the RAM isinhibited from being written. The correct junction of data is detected,and the pickup is moved to the corresponding position. When an underflowis detected, the RAM is released from the write-inhibited state, and anintermittent access is made to resume the writing operation. Thus, eventhough data is written in the RAM at N times the normal speed and readat the normal speed, the output data can be continuously produced.

What is claimed is:
 1. A disk reproducing apparatus for reproducing adisk on which a plurality of digitized information data are recorded andon which subcode including time information relative to the beginningend of each recorded information data are also recorded,comprising:reproduction processing means for processing said digitizedinformation data and said subcodes including time information at N timesa normal output rate at which said reproduced digitized information datais produced, so as to produce a processing output signal in which aparticular one of said information data and a particular one of saidsubcodes is multiplexed always in one-to-one correspondence; output ratesetting means for converting the output rate of said information dataand said subcodes in said processing output signal, supplied from saidreproduction processing means at N times the normal output rate, intothe normal output rate using said one-to-one correspondence between theparticular one of said information data and the particular one of saidsubcodes or maintaining the output rate of said information data andsaid subcodes supplied from said reproduction processing means at Ntimes the normal output rate; and switching means for switching saidoutput rate of said output rate setting means.
 2. A disk reproducingapparatus for reproducing a disk on which a plurality of digitizedinformation data are recorded and on which subcodes including timeinformation relative to the beginning end of each recorded informationdata are also recorded, comprising:reproduction processing means forprocessing said information data and said subcodes including timeinformation at N times a normal output rate at which said reproducedinformation data is produced, so as to produce a processing outputsignal in which a particular one of said information data and aparticular one of said subcodes is multiplexed always in one-to-onecorrespondence; output rate setting means for converting the output rateof said information data and subcodes in said output signal, suppliedfrom said reproduction processing means at N times the normal outputrate, into the normal output rate using said one-to-one correspondencebetween the particular one of said information data and the particularone of said subcodes or maintaining the output rate of said informationdata and said subcodes supplied from said reproduction processing meansat N times the normal output rate; switching means for switching saidoutput rate of said output rate setting means; rotating means forrotating a disk on which modulated said information data and saidsubcodes including a beginning end signal of said information data andtime information are recorded; and information reading means for readingsaid information data and said records from said disk; wherein saidreproduction processing means comprising:processing means fordemodulating said modulated information data and said subcodes read bysaid information reading means, making a predetermined process to detector correct error of said information data, performing a reproductionprocessing at N times the normal output rate, and producing saidinformation data and said subcodes; said output rate setting meanscomprising:first memory means for storing said information data or saidinformation data and said subcodes from said processing means andproducing said information data; and first control means for controllinga write address and read address to said first memory means; saidprocessing means including:second memory means for storing saidinformation data and said subcodes to absorb rotation irregularity ofsaid disk; and second control means for controlling a write address andread address to said second memory means, said second control meansgenerating said write address and read address to said second memorymeans such that said information data which has been interleaved uponrecording is de-interleaved and that a particular one of saidinformation data and a particular one of said subcodes can be read inone-to-one correspondence.
 3. A disk reproducing apparatus forreproducing a disk on which a plurality of digitized information dataare recorded and on which subcodes including time information relativeto the beginning end of each recorded information data are alsorecorded, comprising:reproduction processing means for processing saidinformation data and said subcodes including time information at N timesa normal output rate at which said reproduced information data isproduced, so as to produce a processing output signal in which aparticular one of said information data and a particular one of saidsubcodes is multiplexed always in one-to-one correspondence; output ratesetting means for converting the output rate of said information dataand subcodes in said output signal, supplied from said reproductionprocessing means at N times the normal output rate, into the normaloutput rate using said one-to-one correspondence between the particularone of said information data and the particular one of said subcodes ormaintaining the output rate of said information data and said subcodessupplied from said reproduction processing means at N times the normaloutput rate; switching means for switching said output rate of saidoutput rate setting means; rotating means for rotating a disk on whichmodulated said information data and said subcodes including a beginningend signal of said information data and time information are recorded;and information reading means for reading said information data and saidsubcodes from said disk; wherein said reproduction processing meanscomprising:processing means for demodulating said modulated informationdata and said subcodes read by said information reading means, making apredetermined process to detect or correct error of said informationdata, performing a reproduction processing at N times the normal outputrate, and producing said information data and said subcodes; said outputrate setting means comprising:first memory means for storing saidinformation data or said information data and said subcodes from saidprocessing means and producing said information data; and first controlmeans for controlling a write address and read address to said firstmemory means; said processing means including:second memory means forstoring said information data and said subcodes to absorb rotationirregularity of said disk; and second control means for controlling awrite address and read address to said second memory means, said secondcontrol means generating said write address and read address to saidsecond memory means such that said information data which has beeninterleaved upon recording is de-interleaved and that a particular oneof said information data and a particular one of said subcodes can beread in one-to-one correspondence; said first control means forcontrolling said write address and read address to said first memorymeans including:first detecting means for detecting first sectorinformation which indicates an address at which said information data iswritten in said first memory means from said subcode which are producedfrom said processing means through said second memory means; seconddetecting means for detecting second sector information which indicatesan address at which said information data is read from said first memorymeans; third detecting means for detecting an overflow and underflow ofsaid data stored in said first memory means by comparing said detectedfirst sector information and second sector information; third controlmeans for inhibiting said first memory means from being written whensaid third detecting means detects the overflow and produces theresulting output; fourth control means for moving said reading means toa position of next data continuous to the previous data according tosaid first sector information when said first memory means is inhibitedfrom being written; and fifth control means for releasing said firstmemory means from the write-inhibited state, thereby enabling said firstmemory means to be written when said third detecting means detects theunderflow and produces the resulting output; a first clock frequency fordetermining a speed at which a data is written in said first memorymeans corresponding to N times the normal speed, and a second clockfrequency for determining a speed at which a data is read from the firstmemory means corresponding to the normal speed.
 4. A method ofreproducing a disk on which a plurality of digitized information dataare recorded and on which subcodes including time information relativeto a beginning end of each recorded information data are also recorded,comprising the steps of:processing said digitized information data andsaid subcodes including said time information at N times a normal outputrate, so as to produce a processing output signal in which a particularone of said information data and a particular one of said subcodes ismultiplexed always in one-to-one correspondence; processing saidprocessing output signal by converting the output rate of saidinformation data and and said subcodes, reproduced at N times the normaloutput rate at said processing step, into the normal output rate usingsaid one-to-one correspondence between the particular one of saidinformation data and the particular one of said subcodes, or maintainingthe output rate of said information data and said subcodes supplied insaid first-mentioned processing step at N times the normal output rate;and selecting one of N times the normal output rate and the normaloutput rate to thereby produce a reproduction output signal containingsaid information data.
 5. A method of reproducing a disk on which aplurality of digitized information data are recorded and on whichsubcodes including time information relative to a beginning end of eachrecorded information data are also recorded, comprising the stepsof:processing said digitized information data and said subcodesincluding said time information at N times a normal output rate, so asto produce a processing output signal in which a particular one of saidinformation data and a particular one of said subcodes is multiplexedalways in one-to-one correspondence; processing said processing outputsignal by converting the output rate of said information data and saidsubcodes, reproduced at N times the normal output rate at saidprocessing step, into the normal output rate using said one-to-onecorrespondence between the particular one of said information data andthe particular one of said subcodes, or maintaining the output rate ofsaid information data and said subcodes supplied in said first-mentionedprocessing step at N times the normal output rate; selecting one of Ntimes the normal output rate and the normal output rate to therebyproduce a reproduction output signal containing said information data;rotating said disk which has recorded thereon modulated said informationdata and said subcodes including a beginning end signal of saidinformation data and time information; and reading said information dataand said subcodes from said disk; demodulating said modulatedinformation data and said subcodes read at said information readingstep, making a predetermined process to detect or correct error of saidinformation data, performing a reproduction processing at N times thenormal output rate, and producing said information data and saidsubcodes; storing said information data or said information data andsaid subcodes reproduced at said processing step and producing saidinformation data; controlling said information data to be written andread; and storing said information data and said subcodes to absorbrotation irregularity of said disk; wherein said information data whichhas been interleaved upon recording being de-interleaved and read bygenerating a write address and read address to memory means, and saidsubcodes being read so that a particular one of said information dataand a particular one of said subcode are read in one-to-onecorrespondence, at steps for controlling said information data and saidsubcodes to be written and read.
 6. A disk reproducing apparatus asclaimed in claim 1, wherein said disk reproducing apparatus is moreparticularly a CD disk reproducing apparatus, said information data isat least one of audio data and non-audio data, and said subcodes includesector data.
 7. A disk reproducing apparatus as claimed in claim 2,wherein said disk reproducing apparatus is more particularly a CD diskreproducing apparatus, said information data is at least one of audiodata and non-audio data, and said subcodes include sector data.
 8. Adisk reproducing apparatus as claimed in claim 3, wherein said diskreproducing apparatus is more particularly a CD disk reproducingapparatus, said information data is at least one of audio data andnon-audio data, and said subcodes include sector data.
 9. A method asclaimed in claim 4, wherein said method is more specifically a method ofreproducing a CD disk, said information data is at least one of audiodata and non-audio data, and said subcodes include sector data.
 10. Amethod as claimed in claim 5, wherein said method is more specifically amethod of reproducing a CD disk, said information data is at least oneof audio data and non-audio data, and said subcodes include sector data.11. A disk reproducing apparatus as claimed in claim 1, wherein saiddisk reproducing apparatus is more particularly a mini-disk reproducingapparatus, said information data is audio data and said subcodes includesector data.
 12. A disk reproducing apparatus as claimed in claim 2,wherein said disk reproducing apparatus is more particularly a mini-diskreproducing apparatus, said information data is audio data and saidsubcodes include sector data.
 13. A disk reproducing apparatus asclaimed in claim 3, wherein said disk reproducing apparatus is moreparticularly a mini-disk reproducing apparatus, said information data isaudio data and said subcodes include sector data.
 14. A method asclaimed in claim 4, wherein said method is more specifically a method ofreproducing a mini-disk, said information data is audio data and saidsubcodes include sector data.
 15. A method as claimed in claim 5,wherein said method is more specifically a method of reproducing amini-disk, said information data is audio data and said subcodes includesector data.
 16. A disk reproducing apparatus for reproducing a disk onwhich a plurality of digitized information data are recorded and onwhich a subcodes including time information are also recorded, said diskreproducing apparatus comprising:reproduction processing means forprocessing said digitized information data and said subcodes includingtime information at N times a normal output rate at which saidreproduced digitized information data is produced, so as to produce aprocessing output signal in which a particular one of said informationdata and a particular one of said subcodes is multiplexed always inone-to-one correspondence; output rate setting means for converting theoutput rate of said information data and subcodes in said processingoutput signal, supplied from said reproduction processing means at Ntimes the normal output rate, into the normal output rate using saidone-to-one correspondence between the particular one of said informationdata and the particular one of said subcodes or maintaining the outputrate of said information data and said subcodes supplied from saidreproduction processing means at N times the normal output rate; buffermemory for storing each said information data and said subcodes in saidone-to-one correspondence, wherein said subcode are used to monitorproper continuous storage of each said information data and said subcodein said memory; and switching means for switching said output rate ofsaid output rate setting means.
 17. A disk reproducing apparatus asclaimed in claim 16, wherein said disk reproducing apparatus is moreparticularly a CD disk reproducing apparatus, said information data isat least one of audio data and non-audio data, and said subcodes includesector data.
 18. A disk reproducing apparatus as claimed in claim 16,wherein said disk reproducing apparatus is more particularly a mini-diskreproducing apparatus, said information data is audio data and saidsubcodes include sector data.
 19. A method of reproducing a disk onwhich a plurality of digitized information data are recorded and onwhich subcodes including time information are also recorded, comprisingthe steps of:processing said digitized information data and saidsubcodes including said time information at N times a normal outputrate, so as to produce a processing output signal in which a particularone of said information data and a particular one of said subcodes ismultiplexed always in one-to-one correspondence; processing saidprocessing output signal by converting the output rate of saidinformation data and subcode, reproduced at N times the normal outputrate at said processing step, into the normal output rate using saidone-to-one correspondence between the particular one of said informationdata and the particular one of said subcodes, or maintaining the outputrate of said information data and said subcode supplied in saidfirst-mentioned processing step at N times the normal output rate; andselecting one of N times the normal output rate and the normal outputrate to thereby produce a reproduction output signal containing saidinformation data.
 20. A method as claimed in claim 19, wherein saidmethod is more specifically a method of reproducing a CD disk, saidinformation data is at least one of audio data and non-audio data, andsaid subcodes include sector data.
 21. A method as claimed in claim 19,wherein said method is more specifically a method of reproducing amini-disk, said information data is audio data and said subcodes includesector data.
 22. A disk reproducing apparatus for reproducing a disk onwhich a plurality of digitized information data are recorded and onwhich subcodes including time information are also recorded, said diskreproducing apparatus comprising:reproduction processing means forprocessing said digitized information data and said subcodes includingtime information so as to produce a processing output signal in which aparticular one of said information data and a particular one of saidsubcodes is multiplexed always in one-to-one correspondence; a buffermemory apparatus for receiving said processing output signal for storingeach said information data and said subcode in said one-to-onecorrespondence in a memory, wherein said subcodes of said processingoutput signal are used to monitor proper continuous storage of each saidinformation data and said subcodes in said buffer memory.
 23. A diskreproducing apparatus as claimed in claim 22, further comprising:outputrate setting means for converting an output rate of said informationdata and said subcodes in said processing output signal, supplied fromsaid reproduction processing means at N times a normal output rate, intothe normal output rate using said one-to-one correspondence between theparticular one of said information data and the particular one of saidsubcodes or maintaining the output rate of said information data andsaid subcode supplied from said reproduction processing means at N timesthe normal output rate; and switching means for switching said outputrate of said output rate setting means.
 24. A disk reproducing apparatusas claimed in claim 22, wherein said disk reproducing apparatus is moreparticularly a CD disk reproducing apparatus, said information data isat least one of audio data and non-audio data, and said subcodes includesector data.
 25. A disk reproducing apparatus as claimed in claim 22,wherein said disk reproducing apparatus is more particularly a mini-diskreproducing apparatus, said information data is audio data and saidsubcodes include sector data.
 26. A method of reproducing a disk onwhich a plurality of digitized information data are recorded and onwhich a subcodes including time information are also recorded,comprising the steps of:processing said digitized information data andsaid subcodes including time information so as to produce a processingoutput signal in which a particular one of said information data and aparticular one of said subcodes is multiplexed always in one-to-onecorrespondence; storing, using said processing output signal, each saidinformation data and said subcodes in said one-to-one correspondence ina memory, wherein said subcodes of said processing output signal is usedto monitor proper continuous storage of each said information data andsaid subcodes in said memory.
 27. A method as claimed in claim 26,wherein said method comprises the further steps of:converting an outputrate of said information data and said subcodes in said processingoutput signal, supplied from said processing step at N times a normaloutput rate, into the normal output rate using said one-to-onecorrespondence between the particular one of said information data andthe particular one of said subcodes or maintaining the output rate ofsaid information data and said subcodes supplied from said reproductionprocessing means at N times the normal output rate; and switching saidoutput rate of said converting step to select one of said normal outputrate and said N times a normal output rate.
 28. A method as claimed inclaim 26, wherein said method is more specifically a method ofreproducing a CD disk, said information data is at least one of audiodata and non-audio data, and said subcodes include sector data.
 29. Amethod as claimed in claim 26, wherein said method is more specificallya method of reproducing a mini-disk, said information data is audio dataand said subcodes include sector data.